DIMENSION Subcommand (CORRESPONDENCE command)

DIMENSION specifies the number of dimensions you want CORRESPONDENCE to compute.

• If you do not specify the DIMENSION subcommand, CORRESPONDENCE computes two dimensions.
• DIMENSION is followed by a positive integer indicating the number of dimensions. If this parameter is omitted, a value of 2 is assumed.
• In general, you should choose as few dimensions as needed to explain most of the variation. The minimum number of dimensions that can be specified is 1. The maximum number of dimensions that can be specified equals the minimum of the number of active rows and the number of active columns minus 1. An active row or column is a nonsupplementary row or column that is used in the analysis. For example, in a table where the number of rows is 5 (2 of which are supplementary) and the number of columns is 4, the number of active rows (3) is smaller than the number of active columns (4). Thus, the maximum number of dimensions that can be specified is (5−2)−1, or 2. Rows and columns that are restricted to have equal scores count as 1 toward the number of active rows or columns. For example, in a table with five rows and four columns, where two columns are restricted to have equal scores, the number of active rows is 5 and the number of active columns is (4−1), or 3. The maximum number of dimensions that can be specified is (3−1), or 2. Empty rows and columns (rows or columns with no data, all zeros, or all missing data) are not counted toward the number of rows and columns.
• If more than the maximum allowed number of dimensions is specified, CORRESPONDENCE reduces the number of dimensions to the maximum.